by Vladimir SYVOROTKIN, Cand. Sc. (Geol. & Mineral.), Lomonosov Moscow State University
The natural phenomenon of El Nino that broke out in 1997- 1998 had no equal in scope throughout the history of observations. Small wonder that it happened to be in the limelight in mass media reports. In scientific terminology, El Nino is a complex of interdependent changes in the temperature, pressure and chemical characteristics of the ocean and atmosphere that culminate in natural calamities.
According to the reference literature, this phenomenon is a warm ocean current which, for yet unknown reasons, originates off the shores of Ecuador, Peru and Chile.
Translated from the Spanish, El Nino means "the baby". It has been dubbed this way by Peruvian fishermen due to the warming of ocean waters late in December, on Christmas, and the mass death of fish at that time.
Our magazine (No. 1, 1993) carried a report on this natural wonder.
However, quite a lot of new evidence has been added ever since.
First, in order to understand the anomalous character of El Nino, let us consider the usual, standard climatic situation off the Pacific Coast of South America. It is rather peculiar, this situation, and is determined by the Peruvian Stream that drives the cold water of the Antarctic up the western shores of South America to the Galapagos Islands on the equator. The trade winds blowing from the Atlantic overcome the high barrier of the Andes and bring showers onto the eastern slopes of this mountain system. Therefore South America's western coast is a barren desertland of stone where rainfall occurs but seldom - there could be no precipitation at all in years. The trade winds breaking through to the western Pacific coast, when they are damp enough, give rise to surface currents that, moving westward, cause a piling up of water offshore. The surge is relieved by the counter Cromwell Stream (flowing against the trade winds) in the equatorial zone of the Pacific; this current, 400 kilometers wide and 50 to 300 meters deep, drives huge amounts of water back to the east.
The coastal waters off Peru and Chile are exceedingly productive in the marine fauna. Here, within a small space making up a millesimal fraction of the World Ocean, the fish catch (of anchovy for the most part) is above 20 percent of the world total. The overabundance of fish attracts vast flocks of piscivorous birds - cormorants, pelicans and gannets that fly in to feed on fish. These birds leave mountains of guano, or droppings, which is much in demand as a fertilizer rich in nitrogen and phosphorus; building up a 50 to 100 m layer, this manure is an important export item.
But there comes a dramatic turnabout with the appearance of El Nino. At first the water temperature rises by several points, something that disagrees with the fish population - the fish either leave the waters or die en masse. As a consequence, the fowls of the air disappear too, for there is scare fish for them to feed on. Next, the atmospheric pressure in the East Pacific falls, clouds appear in the sky overhead, and the trade winds die down. The air streams over the equatorial zone of the ocean change direction - now they move from west to east, taking the moisture of the Pacific region and precipitating it on the Peruvian and Chilean coast.
The scenario takes a particular disastrous turn at the foothills of the Andes obstructing the passage of western winds and causing the clouds to precipitate. So the narrow coastal line of desertland (on the western coast) is hit by high-floods, mud and rock torrents, and inundations (and simultaneously, the territories of the West- Pacific Region suffer from terrific drought and its aftermath - forest fires in Indonesia and New Guinea, crop failures in Australia). To cap it all, the so-called "red tides", dubbed so because of the red color imparted by the profuse growth of microscopic algae, turn up all along the western shoreline from Chile up to California.
So, it all begins with the warming of the surface waters in the East Pacific, a phenomenon that is used of late with much success for prognostication of El Nino. This is done with the aid of floating stations (buoys) that measure ocean temperature and relay this information via orbital satellites to research centers. It thus became possible to forecast the worst bout of El Nino in 1997-98.
And yet we cannot tell for sure what the cause of the ocean water warming is, a phenomenon that gives birth to El Nino. Oceanographers explain it by change of wind, while weathermen say the water warming is the cause of the change of wind. A vicious circle!
To come to the understanding of El Nino and its genesis, let us consider some of the factors that escape the notice of expert climatologists.
The following fact is quite obvious to geologists: El Nino takes body and form above one of the most active, geologically, areas of the world rifting system - the East Pacific Rise, where the maximum velocity of spreading (extension of the ocean floor) attains a value of 12-15 cm/yr. The axial zone of this deep-water ridge is remarkable for a powerful heat flow coming from the bowels of the earth; also detected are shows of recent basalt volcanicity, hydrotherms and traces of intensive ore formation as represented by numerous black and white "smokers" (fumaroles).*
Nine streams of hydrogen, escaping from the earth's interior, were found on the ocean floor between 20 0 and 30 0 S. In 1994 an international research party detected the world's largest hydrothermal system there. Its gas composition showed an anomalously high correlation of the hydrogen isotopes 3 He/ 4 He, which means that the head source lies at great depths.
A similar pattern is characteristic of other "hot spots" of the planet too - in Iceland, the Hawaiian Islands, and the Red Sea, where the ocean bottom has powerful centers of hydrogen/methane outgassing which destroy the ozone layer**, mostly in the Northern Hemisphere; this model of mine - that of the ozone layer being destroyed by flows of hydrogen and methane-may be applied to El Nino as well.
Here is our scenario. Hydrogen, escaping from the rift valley of the East Pacific Rise (hydrogen sources were discovered there by instrumental studies) and reaching the water surface, reacts with oxygen; this reaction gives off heat which raises the water temperature. Rather favorable conditions are obtained there for oxidizing reactions: the surface water layer is enriched with oxygen in the course of its wave interaction with the atmosphere.
Well and good, but can the hydrogen rise to the ocean surface in significant amounts? Yes, it can, as it is obvious from the American findings: the concentration of this gas was found to be twice as high over the Gulf of California. And in our case, the hydrogen/methane sources on the ocean floor have a yearly discharge of 1.6.10 8 m 3 .
Hydrogen, rising from the ocean depths into the stratosphere, forms an ozone hole that "sucks in" the ultraviolet and infrared radiation of the sun. Falling on the ocean surface, this UV and IR radiation stimulates the heating of the water that sets in, as we have said, on account of hydrogen oxidation. In fact, this additional energy of the sun appears to be most important for the process. But the role of oxidizing reactions is rather problematic. We might have not considered them at all had it not been for the simultaneous (and rather intensive, from 32.7% to 36%) desalting of the ocean water. Such desalting must be due to the water formed in consequence of hydrogen oxidation.
With the heating of the surface water layer, the solubility of carbon dioxide (CO 2 ) in it diminishes, and this gas is released into the atmosphere. For example, an excess of 6 billion tons of carbon dioxide escaped into the atmosphere when El Nino went on a rampage in 1982 and 1983... Furthermore, the process of water evaporation intensifies, and clouds appear over the East Pacific. Both water vapor and carbon dioxide are what we now describe as hothouse gases; these absorb heat radiation and become an excellent accumulator of the extra energy coming from the ozone hole.
Little by little this process gains in strength and scope. The abnormal heating of the air sends the atmospheric pressure down to give rise to a cyclonic region over the East Pacific. The cyclones upset the normal pattern of trade winds and the atmospheric dynamics in the area; as a result, the air is "pumped in" from the West Pacific. Since the trade winds subside, the water surge recedes from the Peruvian and Chilean shores, and the equatorial counter-current, the Cromwell Stream, is no longer effective. The significant warming of water produces typhoons, which otherwise are quite rare because of the cooling effect of the Peruvian Stream. This area saw ten typhoons in 1980 to 1989, with seven originating in 1982 and 1983, a time when El Nino broke loose.
All that notwithstanding, why is biological productivity so high off the western coast of South America? According to expert estimates, it is as high as in feed-rich fish-breeding ponds of Asia, and 50 thousand(!) times as high as in other parts of the Pacific. This phenomenon is usually explained by up-welling, or the ebb of warm water from shore which causes nitrogen- and phos-
* See: A. Lisitsyn and A. Sagalevich, "Breakthrough Discovery in the Ocean", Science in Russia, No. 1, 2001. - Ed.
** See: V. Syvorotkin, "Hydrogen - the Ozone Killer", Science in Russia, No. 2, 2000. - Ed .
phoras-rich cold water to rise from ocean depths. Now, nitrogen and phosphorus are nutrient components. But El Nino arrests upwelling because of the change of wind, and thus stops the inflow of nutrient water. So the fish and fowl starve or else migrate in search of food.
All that looks like perpetuum mobile, or perpetual motion: profuse organic life in the surface water is made possible by the abundant nutrient stuff coming from beneath and, in turn, the surfeit of this stuff beneath is made possible by profuse organic life above, for the dead organic matter is sedimented on the bottom. What is primary and what is secondary in this circulation? What makes it tick, this circulation, for thousands and thousands of years, judging by the buildup of guano?
The very mechanism of wind upwelling is not clear either. The water rise is usually determined by measuring water temperature on different profiles perpendicular to the shoreline. The isotherms obtained from these data show equally low temperatures off shore and deep underneath. Hence the conclusion about the rising cold waters. However, this method is hardly correct because the Peruvian Stream is responsible for the low temperature off shore. And then another puzzle: the above profiles are across the shoreline, while the prevalent winds blow along it.
I do not intend at all to refute the wind upwelling concept based as it is on a real physical phenomenon. Yet all these problems crop up when we come to deal with this particular zone of the ocean. The anomalous biological productivity of the ocean off the western shores of South America, as I see it, is caused by the outgassing of plutonic matter. Such is my explanation.
In fact, the coastal waters off Peru and Chile do not show the same productivity all along the shore strip, as it should have been in the case of climatic upwelling. Here two "spots" identified, one in the north, and the other in the south; both are controlled by tectonic factors. The first lies above a deep rift extending from the ocean onto the continent south of the Mendana rift (6-8 0 S) and parallel to it. The second spot, somewhat smaller, is located just a bit to the north of the Naska ridge (13-14 0 S). These oblique (diagonal) geological structures extending from the East Pacific Rise toward South America are actually zones of outgassing from which a huge amount of various chemical compounds escapes to the ocean floor. These substances are rich in such vital elements as nitrogen, phosphorus and manganese, and in microelements, too. The coastal waters off Peru and Ecuador have the lowest concentration of oxygen in-depth due to the predominant presence of reduced gases - methane, hydrogen sulfide, ammonia. Yet the thin surface layer (20-30 m) is excessively rich in oxygen owing to the low temperature of water brought in by the Peruvian Stream from Antarctica. This surface layer of water, up above the rift zones supplying the nutrient substances, offers unique conditions for vital activity.
And yet the World Ocean has an area not inferior - perhaps even superior - in bioproductivity. These are the coastal waters of South Africa, likewise thought to be a zone of wind upwelling. But the position of the most productive district (Walfish Bay) is controlled by tectonic factors too, for it is situated above a large rifting zone spreading from the Atlantic Ocean to the African continent north of the Tropic of Capricorn. A cool, oxygen-rich current from Antarctica washes these shores.
The sea off the Kurile Islands, too, is distinguished for the colossal abundance of fish. That's where a cold current passes above the marginal Jonah rift. As good as the entire fishing fleet of Russia heads for the small water area of the South Kurile Straits during the Pacific saury fishing season. It would be in place to name the Kurile Lake in southern Kamchatka where one of our country's largest spawning-grounds of the nerka, or blueback salmon, is situated. This lake is believed to be as productive as that due to the nutrients supplied to its waters by volcanic emanations (this body of water lies between two volcanoes, Ilyinsky and Kambalny).
But back to our baby, El Nino. When the process of outgassing intensifies off the South American coast, the methane and hydrogen thus released blow through the oxygen-rich surface layer of the water teeming with organic life. What happens next is that the oxygen disappears, causing the death of every living wight. And so bones of large fish are trawled from the bottom; and on the Galapagos Islands seals perish in large numbers. But it is unlikely for the fauna to die only because of the dropping bioproductivity of the ocean, as the traditional explanation says. The cause of death comes from the poisonous gases rising from the sea floor. For death occurs suddently, and it is no respecter of organisms, be it phytoplakton or vertebrates. All of the marine community is the victim. But birds fare better: only fledgelings for the most part starve to death - the full-fledged birdies just leave the zone of famine.
However, the decimation of biota off the western shores of South America does not put the lid on lush vital activity there. Lacking oxygen and saturated with toxic gases, such waters are a welcome medium for the proliferation of one-celled algae, the dinoflagellates. This phenomenon is known as a "red tide" because of the abundance of bright algae, red in color, that are quite comfortable under like conditions. Their riot of color is a protection against the ultraviolet rays of the sun - a protective device dating back to the Proterozoic (two billion years ago) when the earth had no ozone layer yet and the bodies of water were the target of intensive UV radiation. So at the time of "red tides" the ocean kind of relapses into its "oxygen-free" past. Because of the overabundance of microscopic algae, some marine organisms, like oysters for example that usually act as water filters, become poisonous and cannot be used for food - they may cause grave poisoning.
My gas-and-geochemical model of anomalous bioproductivity of local districts of the ocean and of recurrent sudden deaths of biota may help explain other phenomena, such as the mass accumulations of fossil fauna in the paleoshales of Germany and in the phosphorites of the Moscow region, or the remains of fish bones filling the shells of cephalopods.
THE MODEL CONFIRMED
Here are some facts to substantiate the outgassing scenario of El Nino.
The years of its violent outbreaks see sharp intensification of seismic activity of the East Pacific Rise, says the American researcher D. Walker who has studied the 1964 to 1992 evidence for the segment of this deep-water ridge between 20 and 40 0 S. But it is common knowledge that seismic events are often accompanied by the enhanced outgassing of plutonic matter. In fact, the "enfant terrible" makes oceanic water swirl with gas. Ship hulls get covered with black spots-a phenomenon called El Pintor, or "painter" in Spanish; and the air over large expanses is filled with the foul odor of hydrogen sulfide.
Walfish Bay in Africa - likewise famous for abnormal bioproductivity - also witnesses periodic ecological crises following the same scenario as those off South America. Discharges of gas cause mass death offish and "red tides", and the stink of hydrogen sulfide is felt even as far as 40 miles inland. Such intense emanations of the gas are usually explained by the decomposition of organic matter on the ocean floor. But does not this hydrogen sulfide come from the bowels of the earth? Our supposition would be more logical, for the gas is released only over the rift zone, and on dry land too, for the rift extends far inland.
Once in the ocean water, the plutonic gases are separated due to their starkly different solubility (this difference amounts to several orders of magnitude). For hydrogen and helium it is equal to 0.0181 and 0.0138 cm 3 in 1 cm 3 of water (at temperature up to 20 0 С and pressure 0.1 Mpa); but for hydrogen sulfide and ammonia the figure is far higher - 2.6 and 700 cm 3 in 1 cm 3 of water. That is why these gases saturate the water over the outgassing zones.
A weighty argument in favor of the outgassing scenario of El Nino is furnished by a chart of the monthly ozone deficit over the equatorial zone; this chart was drawn by the Central Aerological Observatory of Russia's Hydrometeorological Center proceeding from space satellite data. It shows clearly a powerful ozone anomaly above the axial part of the East Pacific Rise south of the equator. Just before this map came out, I had published a qualitative model explaining the possibility of ozone layer destruction just above this zone. That's not the first case when our forecasts of ozone anomalies and their location are confirmed by field observations.
This is the final phase of El Nino - a dramatic cooling of water in the East Pacific with the temperature dropping by several degrees centigrade. This spell of cold persists for a long time. It would be natural to explain this phenomenon by the simultaneous destruction of the ozone layer both above the equator and above the Antarctic. It causes the heating of water in the ocean (El Nino) and the melting of antarctic ice. The huge mass of cold water starts flowing northward. That causes a sharp increase in the temperature gradient between the equatorial and the southern regions of the Pacific. The cold Peruvian Stream is thus intensified, and it cools the equatorial waters after the out-gassing has slackened and the ozone layer is restored.
ORIGINAL CAUSE-IN OUTER SPACE
Now, a few words by way of a plea for El Nino. The mass media, to put it mildly, are not right by accusing it of such calamities as floods in South Korea or severe frosts in Europe. You see, in- depth outgassing may simultaneously intensify in many parts of the world, and this results in the destruction of the ozonosphere and in the appearance of natural anomalies dealt with above. For instance, the warming of water before El Nino occurs also in oceans other than the Pacific.
As to the intensification of plutonic outgassing, it is determined, as I see it, by cosmic factors, mainly by the gravitational effect on the liquid core of the earth containing the bulk of the planetary pool of hydrogen. Here an important role must be played by the disposition of the planets, above all interactions within the system: the earth-moon-sun. Dr. Georgi Voitov and his colleagues at the Joint Institute of Physics of the Earth (RAS) proved it long ago: the outgassing of plutonic matter is intensified in the full and new moon periods. The position of the earth in its circumsolar orbit and change in the rate of its revolution likewise have some effect. The cumulative action of all these external factors, coupled with the effect of processes going on in the earth's interior (for example, the crystallization of the planet's core), may stimulate the planetary outgassing and give birth to phenomena like El Nino. Its 2-7-year pattern of recurrence was established by our researcher Nikolai Sidorenko (Hydrometeocenter) who analyzed a continuous series of atmospheric pressure fluctuations between the Tahiti station (on Tahiti Island in the Pacific) and the Darwin station (northern coast of Australia) for a long space of time, ever since the year 1866.
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